1. Technical Field:
This invention generally relates to electronic rocker switches. In particular, this invention relates to a rugged elastomeric rocker switch assembly particularly suited to hand held controllers such as a hand held radio controller.
2. Background:
Industrial equipment, especially in the construction and locomotive industries, oftentimes requires remote control capability. This is most conveniently accomplished using hand held controllers which are either physically coupled to the controlled unit using an electrical cable or coupled via a radio frequency link using a receiver on the controlled unit and a transmitter in the hand held controller. Incorporating a transmitter in the controlled unit and a receiver in the remote unit allows for remote monitoring of the controlled unit as well as control.
Necessarily, the interface between the user and the hand held transmitter must be rugged to withstand inevitable rough use and inclement weather, but at the same time allow for a high degree of control, be simple to operate and anticipate potential safety hazards.
Prior to the present invention, the interface consisted of a series of toggle switches, a cellular key pad, simple two position slide switches and/or momentary push button switches. Because of the nature of the type of equipment being controlled, different switch actions are necessary. For example, the swing of a crane can be either right or left, making the use of a three position switch desirable, one position for the left direction, one position for the right direction and a neutral position. Similarly, a telescoping boom crane can be extended, retracted or remain set at a particular length. An emergency stop feature is almost always necessary and is most efficiently provided for by a normally open switch which latches closed upon activation and remains closed until manually reset once the hazardous condition has been eliminated.
One of the more common complaints with both toggle switches and momentary push button switches is that they are small and therefor difficult to feel and manipulate, especially when the operator has to wear gloves. Further, both are easily penetrated by dirt and moisture, causing the switch to become inoperable. Attempts to correct this later problem have largely been unsatisfactory. The largest complaint with the cellular key pad interface is that it is all but impossible to feel the action of the individual switches through gloves. Additionally, cellular switches are prone to failure after extended use due to a breakdown of the resilient diaphragm.
What is needed is a rugged switch mechanism which is reliable, simple to operate, water resistant, resistant to penetration by other foreign matter, easily configurable to provide virtually any momentary or latching switch action and which provides both a larger surface area for operator interaction and a pleasant, positive "feel."